\documentclass{ctexart}
\usepackage{avanti}
\everymath{\color{Solarized-magenta}}
\pagestyle{empty} % 没有页眉和页脚

\tikzset{font=\normalsize}

 % define the plot style and the axis style
\tikzset{base/.style={smooth,thick,draw=Solarized-base01}}
\tikzset{arrow/.style={->,>=stealth,base}}
\tikzset{curve/.style={base,Solarized-blue}}
\tikzset{nc/.style={circle, base}}
\tikzset{ms/.style={minimum size=22}}

\begin{document}

\begin{tikzpicture}

    \pgfmathtruncatemacro{\step}{2};

    \node [Solarized-base01,font=\Large] (x7) at (-1.5*\step,0) {输入特征};
    \node [Solarized-base01,font=\Large] (x7) at (-1.5*\step,2) {标准卷积};
    \node [Solarized-base01,font=\Large] (x7) at (-1.5*\step,-2) {微步卷积};

    \node [nc,ms] (x1) at (0*\step,0) {$x_1$};

    \node [nc,dashed,ms] (x2) at (1*\step,0) {$0$};
    \node [nc,dashed,ms] (x3) at (2*\step,0) {$0$};

    \node [nc,ms] (x4) at (3*\step,0) {$x_2$};

    \node [nc,dashed,ms] (x5) at (4*\step,0) {$0$};
    \node [nc,dashed,ms] (x6) at (5*\step,0) {$0$};

    \node [nc,ms] (x7) at (6*\step,0) {$x_3$};

    \node [nc,ms] (a) at (3*\step,2) {$a$};

    \draw [arrow] (x1) -- (a);
    \draw [arrow] (x4) -- (a);
    \draw [arrow] (x7) -- (a);

    \foreach \i in {1,...,5}
        {
            \node [nc,ms] (a\i) at (2*\i,-2) {$a_{\i}$};
        }

    \foreach \i in {1,...,5}
        {
            \pgfmathtruncatemacro{\ip}{\i+1};
            \pgfmathtruncatemacro{\ipp}{\i+2};
            \draw [arrow] (x\i) -- (a\i);
            \draw [arrow] (x\ip) -- (a\i);
            \draw [arrow] (x\ipp) -- (a\i);
        }

\end{tikzpicture}

\end{document}

